Bastard Mods don't need to have nonspecific goals. The only thing that really separates the two is that a Bastard does not follow the informed minority vs. uninformed majority. There might be key information missing, or everyone's informed, or what have you, but there's something different about it.
But, what you've got is a Closed set-up. That means the roles are not known. That's cool, but since you're a new mod, we reeeeeeeeeally want one of the following:
1) To know the set-up, and therefore verify that it isn't blatantly broken in some way or is fun.
2) Have someone verify the above. I suggest Mephansteras or me, since both of us are longtime mods and never play games.
Otherwise, you're going to have a tough time finding players. And even after this, you'll have a tough time finding players, since you're new and all. I suggest running a type of game that has already existed to test your mod skills. Suggestions are:
1) Beginner's Mafia. Easily the top suggestion by far.
2) Mountainous/Near-Mountainous Mafia. Simple to run, and you can't mess up the roles.
3) Kingmaker Mafia. Tougher, but any mod can help set this up if you need it. This one's easy if you are busy, since a lot of the modding is down time.
4) Standard Werewolf/Mafia. We don't have any basic set-ups here, so this might require some mod help or thinking.
5) Bastard Mod. Difficult, and requires lots of approval to run. If people don't know you, they won't join.
6) BYOR Mafia. Err... Don't do it. It's pretty difficult if you're not used to it.
These are just some starters that'll get your modding career going. You can run any type of mafia you want, but if you want bigger crowds, you need to be well-known. And to get well-known, you've got to start somewhere.